Recyclable chiral metathesis catalysts

A chiral metal catalyst of formula (1):

• 12
• wherein:
• M is a polyvalent metal;
• X is oxygen (O) or sulfur (S);
• R is selected from the group consisting of alkyl, alkenyl, alkynyl, aryl, aralkyl, alkoxy, alkenyloxy, alkynyloxy, aryloxy, alkoxy carbonyl, alkylamino, alkylthio, alkylsulfonyl, and alkylsulfinyl;
• wherein each is optionally substituted with an alkyl, halogen, alkoxy, aryl or heteroaryl group;
• R1 and R2 are each independently an electron-withdrawing monovalent or divalent ligand provided at least one of them is a divalent ligand;
• a, b, c, and d are each independently selected from the group consisting of hydrogen, halogen, alkyl, alkenyl, alkynyl, aryl, aralkyl, alkoxy, alkenyloxy, alkynyloxy, aryloxy, alkoxycarbonyl, alkylamino, alkylthio, alkylsulfunyl, and alkylsulfinyl;
• wherein each is independently optionally substituted with an alkyl, halogen, aryl or heteroaryl group;
• Y is an electron-donating ligand;
• and
• Z is an aromatic or heteroaromatic ring substituent that is bonded to Y and to either R1 or R2 provided either R1 or R2 is a divalent ligand.